Mechanical, electrical and optical properties of a cell can be an indication of a cell's physiological state. However, non-destructive methods for measuring such properties of one or more cells can be cumbersome.
Flow cytometers and fluorescence activated cell sorters are indispensable biomedical research and clinical instruments capable of detecting and sorting individual cells at rates significantly higher than 1000 cells/s. The use of such fluorescent labeling techniques may impair investigations where post-sorting cell viability is crucial. Moreover, the fluorescent labels utilized in such methods are considered potentially harmful to the cells.
As a result, but in an effort to retain the broad applicability of such cytometers, there has been increasing interest in label-free biomarkers that allow dependable and accurate cell classification.